Photographic gelatin layers containing the water-soluble salts of various half esters of substituted succinic acid as coating aids



United States Patent "ice Patented .3 15912 3,220,847 H 0 I PHOTOGRAPHIC GELATIN LAYERS CONTAINING R t ll,

THE WATER-SOLUBLE SALTS on vAnroUs HALF nsrnns or SUBSTITUTED SUCCINIC Acn) AS COATING AIDS 5 William J. Knox, .Ir., Rochester, N.Y., and Robert E.

Sticker, Lawrence, Kans., assignors to Eastman Kodak one of R1 and R2 being the other being selected Company, Rochester, N.Y., a corporation of N from the group consisting of alkyl and alkenyl radicals Jersey containing 8-16 carbon atoms having at least two points No Drawing. Filed Feb. 23, 1962, Ser.No. 175,284 of branching; M is a cation such as Na, K, NH or 13 Claimsalkylammonium; Q is the radical derived from a watersoluble alcohol containing 3-19 oxygen atoms in the form of hydroxyl or ether groups; and m is an integer from 1-8, being 1 when Q is the radical derived from a monohydroxy alcohol and 2-8 when Q is the radical derived from a polyhydroxy alcohol.

It may be seen that generally two isomeric forms of the compounds of our invention are possible. Thus, referring to the generic formula shown above, it is apparent that the branched-chain alkyl or alkenyl radical may be positioned on the succinic radical beta or gamma to the half ester. It is believed (but not known) that one isomer predominates in the normal preparation of the compounds of this invention. In any event, a mix- 25 ture of the isomers appears satisfactory in employing the compounds of the invention as coating aids in protein coating compositions.

The alcohol, from which the desired half esters are derived, is not critical so long as the alcohol is a watersoluble compound containing from 3-19 oxygen atoms in the form of hydroxyl or ether groups. By the term ether we mean to include acetals and ketals also. Representative alcohols include 2-(2-ethoxyethoxyl)ethanol, anhydroenneaheptitol, glycerol, sorbitol, 2,2,6,6 tetramethylolcyclohexanol, pentaerythritol, 2,2,6,6,10,l0-hexamethyl0l-4,8-oxaundecamethyleneglycol (trimer of pentaerythritol), and the like. A particularly useful alcohol for our purpose is a sucrose derivative, called Hyprose SP-80 hereinafter, having the formula:

CHgOCHzOHOHCHs CHaOCHzCHOHCH:

This invention relates to coating aids for gelatin coating solutions particularly those used for photographic purposes which are in the nature of water-soluble salts of half esters of branched-chain substituted succinic acids. 15

In the application of gelatin coating compositions, particularly gelatin-silver halide photographic emulsions, to a support such as film base or paper, it is desirable that there be present therein a coating aid to facilitate the application of the gelatin layer to the surface of the support. This application of gelatin compositions can be either in the form of a single layer or in multilayer form such as by the simultaneous application of a plurality of layers to a support. The presence of coating aids in the coating or coatings assists in obtaining layers which in the form of dry coatings are free of defects such as repellencies, pencil line streaks, and the like. In such coating operations, however, the coating aids that induce adequate rewettability of the gelatin layer usually also impart slickness or slipperiness thereto. This surface slickness in photographic products is generally objectionable because of difliculties in handling and the possibility of telescoping when film is in roll form. It has often been necessary to use a mixture of two different surfactants to impart both surface roughness and rewettability to gelatin coatings. The mixing of two different coating aids is often times undesirable, and some of the materials which have been proposed for that pur- H n l oonzononoik 0 H F" H HsCCHOHHzCO I x CHgOCHzCHOHCH3 l HO H OCHzC'HOHCHa OCH2CHOHOH3 H OCHZCHOHCHQ pose are naturally occurring and often vary in quality The compounds useful in this invention may be preor contain impurities undesirable in photographic use. pared by reacting the desired branched-chain alkyl or al- One object of our invention is to provide gelatin coatkenyl succinic anhydride with the desired alcohol, foling compositions from which layers having both adel wed by neutralization with a base such as sodl Y' quate rewettability after drying and sufficient roughness droxlde- Pamclllarly Valuable coatlllg alds y be P pared by reacting commercially available dodecenylsuccinic anhydride (wherein the dodecenyl radical is a mixture of branched monoolefins formed by tetramerizing propene) with an alcohol. The structural formulas of the coating aids thus produced are indicated below; it being understood that the dodecenyl substituent may be attached to either of the carbon atoms of the hydrocarbon portion of the succinic acid radical:

COMPOUND I C gH sCHCOOCHgCHgOCHgCHnOCzHs HgCOONa COMPOUND II on onzon onion of surface to facilitate handling may be obtained. Another object of our invention is to provide gelatin coating compositions from which may be prepared coatings that when dry have few if any repellencies, pencil line streaks, or other undesirable characteristics. A fur that object of our invention is to provide gelatin coat- 60 ing aids comprising certain half esters of branched-chain substituted succinic acids. Other objects of our invention will appear herein.

We have found that the water-soluble salts of various half esters of branched-chain succinic acids when incorporated in photographic emulsions or other gelatin coating compositions may be used in preparing products exhibiting good handling characteristics. Coating aids which we have found to be particularly useful when in- CHHKPCHC 0 OOHZ cHgoH corporated in gelatin compositions are those having the HOOON formula: 2 a

COMPOUND III CuHzs-CHC O O CHzCHOHCHzOH HgCOONa COMPOUND -IV C ;H 3CHC O O CH1(GHOH 4CH2OH CH C O ONa COMPOUND VII 1rHg3-CHC O O-Hyprose SP8O H 6 0 O Na COMPOUND VIII (C E -4311C 0 O Hyprose SP-SO H20 0 ONa):

COMPOUND IX (C1gHg3C HC 0 0 Hyprose SP-80 01120 O 0Na COMPOUND X 12H23 'CHC O O HzC O 0N8);

C(IMPOUND XI 12 2aCHC O O CH;

CHzCOONa C HOH2C COMPOUND XII C gHzaCHC O- CHzC O 0N3 COLIPOUND XIII Hyprose SP-SO GHzOH CHzOH The dodecenyl radical of the above compounds contains not less than two points of branching, and generally is a highly branched monoolefin radical. As indicated above, various other alkyl and alkenyl substituted hydrogen succinates may be employed in accordance with this invention. Representative half esters include those derived from the following acid: a hydrogen tetramethylbutylsuccinic acid, sodium salt; a hydrogen branchedchain dodecylsuccinic acid, soduim salt; a hydrogen branched-chain tridecylsuccinic acid, sodium salt; a hydrogen branched-chain pentadecylsuccinic acid, sodium salt; a hydrogen branched-chain hexadecylsuccinic acid, sodium salt; a hydrogen branched-chain nonenylsuccinic acid, sodium salt; a hydrogen branched-chain pentadecenylsuccinic acid, sodium salt; and, a hydrogen branched-chain hexadecenylsuccinic acid, sodium salt. In each of the foregoing compounds, the alkyl or alkenyl radical contains not less than two points of branching. Of course the half ester portion in these compounds conform to the general description of the alcohols given above.

We have found that when these compounds are incorporated in small amounts in aqueous solutions of gelatin good coating properties are obtained. This has been found to be true both in coating operations in which a single layer has been applied to film base or paper in mixed coating operations such as described in US. 2,761,991 of T. A. Russell. It was found that any amount of coating aid present in the gelatin composition was effective, however, it is convenient to operate within the coating range of 0.5-15%, based on the weight of the gelatin, and preferably 110% is employed.

In the coating aids in accordance with our invention it is desirable that the branched-chain substituent attached to the hydrocarbon portion of the succinic acid radical have 8-16 carbon atoms. In many cases as will be noted from the formulae, the radical derived from an alcohol will be that derived from a polyhydroxy alcohol and therefore the compounds can comprise more than one succinyl group per unit structure of compound.

The following examples illustrate the preparation of compounds useful as coating aids in accordance with our invention.

Example A A homogeneous mixture of 532 parts (2.0 moles) of dodecenylsuccinic anhydride and 268.4 parts (2.0 moles) of 2-(2-ethoxyethoxy)ethanol was heated on a steam bath for four hours. The resulting product was cooled to room temperature, diluted with 1000 parts of water and while stirring was neutralizedwith 80 parts (2.0 moles) of sodium hydroxide in 10% aqueous solution. After mixing for one hour, the solution was diluted with water to represent a 25% solution of coating aid, i.e. 2 (2 ethoxyethoxy)ethyl hydrogen dodecenylsuccinate, sodium salt (Compound 1).

Example B A mixture of 56.6 parts (0.213 mole) of dodecenylsuccinic anhydride, 38.8 parts (0.213 mole) of sorbitol and 0.5 part of anhydrous p-toluenesulfonic acid were 3 mixed into 200 parts of acetone and the mixture was refluxed for four hours. Acetone was then boiled off from the resulting clear solution to give a clear, yellow liquid which was diluted with 100 parts of water and neutralized with 8.5 parts (0.213 mole) of sodium hydroxide, in 10% aqueous solution.

The mixture while stirring was heated on a steam bath for two hours and then was diluted with water to form a 20% solution of coating aid, i.e. sorbityl hydrogen dodecenylsuccinate, sodium salt (Compound IV).

Example C 32.1 part (0.236 mole) of pentaerythritol and 62.8 parts (0.236 mole) of dodecenylsuccinic anhydride were mixed and the mixture was heated for fifteen minutes at 195210 C. The mixture was allowed to cool to and was then diluted with parts of water. While stirring and maintaining the temperature at 70 C., there was added 9.4 parts (0.236 mole) of sodium hydroxide in 10% aqueous solution. The mass was mixed for an hour and was diluted to form a 25% solution of coating aid, i.e. pentaerythrityl hydrogen dodecenylsuccinate, sodium salt (Compound XI).

Pentaerythrityl tris(hydrogen dodecenylsuccinate, so dium salt) (Compound XII) was prepared in a similar manner but proportionate amounts of materials were employed.

Example D The water was removed from 59.5 parts (0.196 mole)- of 70% aqueous anhydroenneaheptitol by evaporation,. in vacuo, on a steam bath. Thereupon 52.2 parts (0.196- mole) of dodecenylsuccinic anhydride were added and the stirred mixture was heated for 30 minutes at C. Cooling to room temperature resulted in a yellow, tacky, clear glass which was powdered and dissolved in 7.8 parts (0.196 mole) of sodium hydroxide in: 10% aqueous solution. The resulting solution was diluted with water to form a 25% solution of the coating aid, i.e. the sodium salt of 3,3,5,5-tetramethylol-4-byranol monoester of dodecenylsuccinic acid (Compound II). The disodium salt of the diester of 3,3,5,5 -tetramethylol-4- byranol was prepared in a similar manner from 2 moles of dodecenylsuccinic anhydride per mole of anhydroenneaheptitol.

Example E A mixture of 73.7 parts (0.0913 mole) of Hyprose SP-80 [octakis(2-hydroxypropyl)sucrose] and 24.3 parts (0.0913 mole) of dodecenylsuccinic anhydride was heated at 140-160 C. A homogeneous mixture was obtained and was allowed to cool to 80 C. and was then diluted with 100 parts of water and neutralized with 3.7 parts of sodium hydroxide while maintaining the temperature at 60-70 C. After a thorough mixing, the solution was diluted to form a 20% solution of coating aid (Compound VII).

In a similar manner Hyprose SP-SO tris(hydrogen dodecenylsuccinate, sodium salt) (Compound VIII), Hyprose SP80 pentakis(hydrogen dodecenylsuccinate, sodium salt) (Compound IX), and Hyprose SP-80 heptakis(hydrogen dodecenylsuccinate, sodium salt) (Compound X), were prepared using proportional amounts of materials in their preparation.

The following examples illustrate the use of these coating aids in applying coatings. A coating experiment in which an aqueous solution of gelatin was applied by a hopper coating method as a single layer to cellulose ester film base using 0.22 gram of the coating aids designated per pound of coating composition.

The following results were obtained:

Example 2 There was simultaneously applied to paper a photographic emulsion coating and .a gelatin overcoating both of which contained Compound VII by means of the coating technique described in US. 2,761,991 in the proportions indicated together with a control in which saponin coating aid was employed. It was found that the paper thus obtained was more responsive to developer spread than the control coatings while the coefiicient of friction was not appreciably altered.

Surfactant Concentration Repelemul. overcoat Developer Coef. of lencies Spread Friction (7.5 it?) (G./lb.) (G./lb.)

Compound VII- 0. 13 0. 5 12. 60 0.398 None 0. 25 0. 5 10. 20 0. 320 None 0. 5 0. 5 11. 30 0. 332 2-3 Control 0. 25 U. 5 7. 55 0.332 None In the above data repellencies refers to the number of dull and uncoated spots in the area designated whether 25 square feet or 7.5 square feet.

Developer spread was determined by delivering in a standard manner one cc. of developer solution to a surface of photographically sensitized paper carrying a clear gelatin overcoat, and measuring the area which develops in a period of 30 seconds. This test indicates how effec- 6 tively an emulsion will wet. A developer spread of 4.0 0111. or more is desirable.

The coetficient of friction was determined by placing the coated side of photographically sensitized paper carrying a gelatin overcoat against the uncoated side of a similar sheet. The coefiicient of friction was measured to obtain the slickness of the gelatin coatings. Difficulties occur in stacking coated sheets when the coefficient of friction is less than about 0.25.

We claim:

1. A composition comprising gelatin having therein a water-soluble coating aid having the formula:

H o natal in which one of R and R is H, the other being selected from the group consisting of alkyl and alkenyl radicals of 8-16 carbon atoms having at least two points of branching; M is a water solubility imparting cation; Q is the radical of a water-soluble alcohol containing 3-19 carbon atoms in the form of groups selected from the hydroxyl and ether groups and n is an integer of 18, being 1 when Q is a radical of a monohydroxy alcohol and 2-8 when Q is a radical of a polyhydroxy alcohol.

2. A photographic emulsion comprising silver halide grains carried by a gelatin vehicle which gelatin contains a water-soluble coating aid having the formula:

in which one of R and R is H, the other being selected from the group consisting of alkyl and alkenyl radicals 816 carbon atoms having at least two points of branch ing; M is a water solubility imparting cation; Q is the radical of a water-soluble alcohol containing 3-19 carbon atoms in the form of groups selected from the hydroxyl and ether groups and n is an integer of 1-8, being 1 when Q is a radical of a monohydroxy alcohol and 2-8 when Q is a radical of a polyhydroxy alcohol.

3. A composition of matter comprising gelatin containing as a coating aid therein a water-soluble salt of 2-(2- eth0xyethoxy)ethy1 hydrogen dodecenylsuccinic acid.

4. A gelatin-silver halide photographic emulsion containing a water-soluble salt of 2-(2-ethoxyethoxy)ethyl hydrogen dodecenylsuccinic acid.

. 5. A composition of matter comprising gelatin containing as a coating aid therein a water-soluble salt of sorbityl hydrogen dodecenylsuccinic acid.

6 A gelatin-silver halide photographic emulsion containing a water-soluble salt of sorbityl hydrogen dodecenylsuccinic acid.

7. A composition of matter comprising gelatin contaming as a coating aid therein a water-soluble salt of pentaerythrityl hydrogen dodecenylsuccinic acid.

8. A gelatin-silver halide photographic emulsion contaming a water-soluble salt of pentaerythrityl hydrogen dodecenylsuccinic acid.

9. A composition of matter comprising gelatin containlng as a coating .aid therein a Water-soluble salt of 3,3,5,S-tetramethylol-4-byranol monoester od dodecenylsuccinic acid.

10. A gelatin-silver halide photographic emulsion containing a water-soluble salt of 3,3,5,5-tetramethylol-4- byranol monoester of dodecenylsuccinic acid.

11. A composition of matter comprising gelatin containing as a coating aid therein a water-soluble salt of Hyproseoctakis(hydrogen dodecenylsuccinic acid).

12. A gelatin-silver halide photographic emulsion containing a water-soluble salt of Hyprose-80 octakis(hydrogen dodecenylsuccinic acid).

13. A composition of matter comprising gelatin con- References Cited by the Examiner UNITED STATES PATENTS Simmons et a1. 96109 Christopher et a1. 106125 Salzberg et a1. 106-125 Gray et a1 9694 10 Gray 9694 8 Milton et a1. 9694 Harriman 9694 Knox et a1. 9694 Milton et a1. 9694 Knox et a1. 9694 Albus et a1. 9694 Knox et a1. 9694 Russia.

NORMAN G. TORCHIN, Primary Examiner. 

1. A COMPOSITION COMPRISING GELATIN HAVING THEREIN A WATER-SOLUBLE COATING AID HAVING THE FORMULA:
 2. A PHOTOGRAPHIC EMULSION COMPRISING SILVER HALIDE GRAINS CARRIED BY A GELATIN VEHICLE WHICH GELATIN CONTAINS A WATER-SOLUBLE COATING AID HAVING THE FORMULA: 